Fishmeal is used as a valuable source of nutrients in many diets for aquaculture species, however nutritional value can vary.
Protein and amino acids are major constituents of fishmeal. Degussa has analyzed amino acid content in over 15,000 fish meal samples over the last five years, providing a unique insight in to the variation of fish meal quality and Mr. Dhanapong Sangsue, Technical Sales Manager Evonik Degussa (SEA) Pte. Ltd. will review mino acids levels in fishmeal in Southeast Asia at the upcoming Aquafeed Horizons Asia Conference.
The variation of amino acid levels and their potential impact on diet formulation and economics is demonstrated based upon over 1,000 fishmeal samples analyzed by wet chemistry in the last five years. For example, total methionine (Met) content ranged from 0.35% to 2.74% and averaged at 1.46%, crude protein (CP) ranged between 30% and 86% with an average of 61%. Respective coefficients of variation were 30.3% for Met and 16.9% for CP.
Regression equation were developed allowing for estimation of amino acid levels in fishmeal from protein content, however using those calculated numbers includes a relatively high inaccuracy with r2 ranging from less than 0.50 to 0.88 across a range of essential amino acids. This is due to the large variation in the amino acid profile of fishmeal when expressed as a % of protein for these samples this varied between 0.86% and 3.24%. A large portion of the variation might be explained by origin of fishmeal. For example, analyses of blue whiting samples revealed average Met and CP contents of 2.01% and 69.7%, respectively, with variation coefficients of only 2.7% and 2.2%.
There are, however, also examples that even within defined materials such as sardine meal the variation coefficient is high (37.5% Met, 19.3% CP).
With regards to Southeast Asia in 2010, 266, 387, 241, 209, and 39 samples of local fishmeal from Vietnam, Thailand, Philippines, Indonesia, and Malaysia were analysed; crude protein contents in the fish meal samples ranged from 56.23 to 63.18 % (variation of coefficient 4.59 - 9.23%), Methionine contents ranged from 1.34 - 1.75% (variation coefficient 6.41 - 14.18%), Lysine contents ranged from 3.61 - 4.71% (variation of coefficient 7.46 - 14.37%)
Clearly, processing of fish meal does not lead to standardization of quality and high variation remains. In order to better meet amino acid specifications in feed formulation and thus reduce safety margins composition of the used fishmeal should be known. This also directly impacts the continuing sustainability of fishmeal use in aqua feed, detailed knowledge of the fishmeal composition leads to increases efficiency and optimal use of limited resource.
While wet chemistry is the reference for amino acid determination, it is a time consuming and expensive method. A solution for this dilemma is the use of rapid NIR technique. Evonik-Degussa developed calibrations with high robustness and precision for amino acid determination of fish meal. AMINONIR® has been recognized by the global feed industry to be highly valuable as demonstrated by the tripling of the annual number of samples analyzed from about 2200 in 2005 to more than 7300 in 2009.
Aquafeed Horizons Asia takes place February 15, 2012, during the region's major feed industry trade show, Victam Asia 2012 at the BICC, Bangkok, Thailand. Details and registration are available at the conference website: www.feedconferences.com. Special rate "early bird" registration closes October 31, 2011.
